|order in position|president of the republic|length of the presidential action|rank by length of term(s)|notes|
|---|---|---|---|---|
|1|K. J. Ståhlberg|5 years, 220 days|8|1 term serving|
|2|Lauri Kristian Relander|6 years, 0 days one leap year (1928)|6|1 term serving|
|3|P. E. Svinhufvud|5 years, 364 days two leap years (1932 and 1936)|6|1 term serving|
|4|Kyösti Kallio|3 years, 293 days|9|* resigned due to poor health|
|5|Risto Ryti|3 years, 229 days|10|* resigned due to agreement with Nazi Germany (after remainder of Kallio's term and during 1 additional, exceptionally 2 years long term)|
|6|Gustaf Mannerheim|1 year, 219 days|11|* resigned due to poor health and after not being prosecuted in war responsibility trials|
|7|J. K. Paasikivi|9 years, 356 days|4|2 terms serving (remainder of Mannerheim's and 1 whole)|
|8|Urho Kekkonen|25 years, 332 days|1|3 whole terms serving (the 3rd exceptionally 10 years) * resigned during the 4th term due to poor health|
|9|Mauno Koivisto|12 years, 33 days|2|2 terms serving|
|10|Martti Ahtisaari|6 years, 0 days two leap years (1996 and 2000)|5|1 term serving|
|11|Tarja Halonen|12 years, 0 days|3|2 terms serving|
|12|Sauli Niinistö|2 years, 115 days|incumbent: first term serving|incumbent: first term serving|

Question: what is the number of presidents who resigned?
Answer: 4